Sizing composition and glass fibers treated therewith

ABSTRACT

A SIZING FOR GLASS FIBERS, COMPRISING WATER SOLUBLE EPOXY RESIN, AN ORGANOSILANE, POLYVINYL ACETATE COPOLYMER AND A LUBRICANT IS PROVIDED, WHEREBY THE SIZED GLASS FIBERS IN THE FORM OF STRANDS, POSSESS EXCELLENT INTEGRITY.

United States Patent Office 3,817,898 Patented June 18, 1974 3,817,898SIZING COMPOSITION AND GLASS FIBERS TREATED THEREWITH John E. Ward,Houghton, Mich., assignor to Owens- Corning Fiberglas Corporation NoDrawing. Application Nov. 15, 1971, Ser. No. 198,940, which is adivision of application Ser. No. 25,584, Apr. 3, 1970, now Patent No.3,652,326. Divided and this application Apr. 9, 1973, Ser. No. 349,145

Int. Cl. C08f 45/24 US. Cl. 26029.6 NR 4 Claims ABSTRACT OF THEDISCLOSURE A sizing for glass fibers, comprising water soluble epoxyresin, an organosilane, polyvinyl acetate copolymer and a lubricant isprovided, whereby the sized glass fibers in the form of strands, possessexcellent integrity.

This is a division of application Ser. No. 198,940, filed Nov. 15, 1971,which is a division of application Ser. No. 25,584, filed Apr. 3, 1970,which is now US. Pat. No. 3,652,326.

BACKGROUND OF THE INVENTION This invention relates to glass structuressuch as glass fibers in which the surface characteristics of the glassstructure have been modified to enable the glass fibers, 1n strand form,to be chopped without losing their integrity, while possessing otherfavorable characteristics. Some of the other favorable characteristicspossessed by the chopped strands include: flowability of the choppedstrands during processing, mixing, handling, conveying and moldingwithin a resinous matrix; low bulk density; heat resistance; lightnessof color; and the chopped strands impart high impact strengths toresinous matrices due to a strong bonding relationship between the sizedchopped strands and the resinous materials, whether thermoset orthermoplastic.

Difiiculties in the establishment of a chopped glass strand thatpossesses integrity during processing, flowability during processing,lightness in color and which imparts high impact strengths to resinousmatrices are well known in the art.

From the time of formation of glass fibers to the more distant point intime of their incorporation into a resin matrix to reinforce the same,many processing operations will have had to be carried out. Immediatelyafter the glass fibers are formed and traveling at linear speeds inexcess of 10,000 ft./min. a protective coating is applied to the glassfibers to prevent mutual abrasion. Subsequently, the sized fibers aregathered onto a rotating collection package or routed directly to achopping apparatus where the glass strands are chopped into lengthsranging from A; to /3 inches.

When the strands are gathered onto a package it is preferable to dry thepackage prior to positioning the package on a creel with numerous otherpackages, so that a plurality of sized strands may be subsequently fedto a chopping machine. When the strands are fed directly to the chopper,the drying may be prior to or subsequent to chopping. When the strandsare dried prior to being chopped a less integral strand res'ults whereaswhen the strands are chopped subsequent to chopping a highly integralstrands results. Because of the differences in integrity the amount ofsolids of the sizing on the glass fibers may be adjusted accordingly tocompensate therefor.

Subsequent to chopping, the chopped strands may be either packaged for alater use or be combined and mixed with a resinous material to form apremix which is used as a molding compound. Finally the molding compoundmay be either packaged for subsequent use or may be immediately used ina molding operation to form reinforced articles.

The treatment applied to the glass fibers at forming must bemultifunctional for the purposes of this invention. It must be capableof protecting the individual fibers from mutual abrasion, capable ofholding the strand in an integral unit before, during, and afterchopping, capable of exhibiting antistatic characteristics so thatduring handling, conveying, mixing and molding, the chopped strands haveflowability and capable of a strong bonding relationship with a resinousmatrix that is to be reinforced.

Difficulties in the establishment of a strong and permanent bondingrelationship between the surfaces of glass fibers and a resinousmaterial have in general become Well known in the art. Because of thenon-porous character of glass fibers, as distinguished from a highdegree of porosity available in natural fibers such as the fibers ofcellulose, wool, cotton, hemp and the like, penetration of resinousmaterials into the fibers is not available for use in establishing abonding relationship between such glass fibers and a resinous material.Because glass fibers naturally form into elongate rods having verysmooth surfaces, as distinguished from the rough surface characteristicsof natural fibers, a gripping relationship or a mechanical bonding isdiificult to establish between resinous materials and the untreatedglass fiber surfaces. Thus a physical anchorage of the type relied uponchiefly for the establishment of a bonding relationship between naturalfibers and resinous materials is not capable of being developed withglass fibers. Glass fibers may be etched or roughened to present asurface of some porosity but desirable strength characteristics of theglass surfaces are simultaneously lost.

In the absence of the ability to make use of physical forces in bonding,it becomes necessary to rely upon the development of a relationshiprequiring chemical bonding or physical-chemical forces based uponmolecular or ionic attraction and the like. With synthetic resinousfibers e.g. nylon, polyester, etc. a strong bonding relationship can bedeveloped with the smooth surfaces because such fibrous materials areresinophilic in character and therefore are preferentially receptive toresinous treating materials. In addition, the resinous materials, ofwhich the fibers are formed, have the ability of being softened by heator solvent in a manner to enable the development of a desired bondingrelationship with the applied treating material. Such chemical forcesresulting from the softening of the synthetic fiber surfaces are notavailable with glass fibers because the glass fibers are inert to heatand solvents and because the glass fiber surfaces are dominated bygroups that are hydrophilic in character and therefore receive moisturein preference to resinous materials. As a result, only a weak bondingrelationship is capable of being established in the first instance andeven this limited bonding is reduced in the presence of moisture or highhumidity suflicient to cause a moisture film to form and separate theresinous coating from the glass fiber surfaces with a moistureinterface.

When a strong bonding relationship cannot be established between glassfibers and a resinous material used in combination therewith, maximumutilization of the strength properties of the glass fibers cannot bemade available in the products that are formed. Even where a fairbonding relationship between glass and resin can be established underextremely dry conditions, the strength properties of the glass fiberreinforced plastic composite depreciates greatly under high humidityconditions or in the presence of moisture.

When glass fibers are formed into strands, containing many fibers, andthe strands are subsequently chopped into lengths of from about /8 inchto about inch, it is desirable to have the chopped strand possessintegrity. That is, after chopping it is desired to have the strand in arod-like manner without the many fibers making up the strand separatingfrom the rod-like structure. The desirability of this rod-like structureis important when a resinous matrix is to be reinforced with glassfibers to improve strength and other characteristics. Another desirablecharacteristic of the chopped strands of this invention is that theyhave a high degree of flowability during processing, especially withinthe resin matrix that is to be reinforced so that the chopped strandshave a uniform dispersement Within the matrix and not be heavily groupedin one local concentration and void of chopped strands in anotherconcentration.

It is therefore an object of this'invention to produce a treatment forglass fibers and to produce glass fibers treated with a material toenable the glass fibers, in strand form, to be chopped without losingtheir integrity during processing.

It is another object of the invention to provide a new and improvedcoating for glass fibers so that the coated fibers, when gathered into astrand, chopped, and subsequently used as a chopped reinforcement inresinous matrices, remain flexible and substantially insoluble in thematrices.

It is another object to produce glass fibers, when when chopped, possessgood flowability characteristics during processing.

It is still another object to produce glass fibers, which whenincorporated with a resinous matrix, exhibits a strong bondingrelationship with the matrix.

Further objects and advantages of the invention will be come apparent tothose skilled in the art to which the invention relates from thefollowing description.

Flowability of chopped strands becomes extremely important during theintroduction of the treated strands to the chopper. It is desirable toobtain chopped strands of uniform length, but this becomes difiicultwhen the chopper becomes clogged with previously chopped fibers. Staticforces are set up on chopping and must be combated.

The lack of strand integrity during processing is more than a problem.It is detrimental to the uniform distribution of chopped strands withina resinous matrix because the strands agglomerate or clump together.When a thermosetting matrix is to be reinforced, a premix, comprisingthe chopped strands and the resin, is formed. When a thermoplasticmatrix is to be reinforced, the chopped strands and resin are introducedinto an injection molding machine as a dry blend via vibration. Iffilamentation of the chopped strands occurs, the strands will tend tostick together through physical or static forces, and cause anon-uniform distribution of the strands into the matrix, or anon-uniform distribution of the strands into the injection moldingmachine.

The degree of integrity possessed by the chopped strands becomesextremely important when the strands are incorporated with a resinousmatrix. During the incorporation it is desirable to obtain somefilamentizing of the strand suflicient to increase the surface area ofavailable reinforcement, but insufi'icient to be incapable of actualreinforcement. It has been found that when the strands have no degree offilamentation upon incorporation with a resinous material, strengths ofthe composite are low. The same phenomenon is present when there is nointegrity of the chopped strand after incorporation of the strand withthe resinous matrix. Therefore, a compromise between a highly integratedstrand and a highly filamentized strand must be reached. Chemical aswell as physical forces con tribute to the degree of filamentation ofthe treated strand, after incorporation into a resinous matrix.

The inventive treatment, hereinafter described in greater detailprovides all of the advantages as above described.

SUMMARY OF THE INVENTION According to the present invention it has beendiscovered that impact strengths of resinous matrices reinforced byshort lengths of glass fibers are greatly increased if the short lengthof fibers are in the form of a strand having some degree offilamentation, rather than dispersed throughout the resin as individualfilaments or small groups of filaments. The inventive treatment whichbonds the fibers together into a strand is of low or intermediatemolecular weight, so that it is flexible, but is crosslinked to arelatively insoluble degree and capable of holding the fibers togetherin the form of a strand during processing. Residual reactivity of thetreatment provides a controlled bonding between the treatment on thesrands and the maritx resin.

According to the invention, the film former within the treatment iscapable of partial reaction during the fiber forming operation to forman integral strand and it is capable of further reaction whenincorporated in a resinous matrix, to provide a controlled degree ofattachment between the surface of the fibers and the matrix resin. Thecoating on the fibers is generally immobile or in a solid state, and thedegree of bonding which is achieved between the strand coating and thematrix resin is a limited or controlled one, which allows the bondbetween the strand and the matrix resin to yield under a concentratedload, such as occurs during impact. Concentrated loads cause some ofthese bonds to be broken to allow the strand to move. It appears thatsome degree of filamentation of the treated strand is necessary uponincorporation of the strand with the resin matrix so that a synergisticsystem is developed.

In a preferred form of the invention, individual glass fibers are coatedat forming with a water dispersion comprising a low or intermediatemolecular weight polyvinyl acetate copolymer, a metal acid catalyst, anda combination of epoxy resins modified to act as lubricants. After theindividual fibers are coated with the dispersion, they are gatheredtogether into a strand and collectedon a package and dried at atemperature which causes the polyvinyl acetate copolymer to crosslink.The crosslinking of the polyvinyl acetate copolymer causes the coatingto set up sufficiently, so that it is flexible but substantiallyinsoluble in a solution of matrix resin. The matrix resin may be astyrene solution of a crosslinking polyester resin, or may be an organicsolution of some other unsaturate such as polypropylene, polyethylene,or polystyrene. When the coated strand is mixed with the matrix resinand cured at a temperature above the drying temperature employed atforming to crosslink the coating material, a polymeriza tion of thematrix resin is produced, and a limited number of bonds are formedbetween the surface of the strand coating and the matrix resin. Thelimited number of bonds between the solid coating material and thematrix resin becomes sequentially broken when subjected to concentratedloads, to allow a yielding of the matrix resin relative to the strand,and a consequent redistribution of the load over a number of strands. Inaddition, the coated strands are locked into the resin matrixmechanically upon polymerization of the resin matrix. A considerableimprovement in impact strength is thereby produced.

The metal acid catalyst or Lewis Acid is selected from a general classof soluble metal salts of the transition metals. These include aluminum,calcium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel,copper, zinc and strontium. Metal chlorides such as AlCl and metalnitrates are the preferred metal salts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Example I A sizing compositioncomprising an aqueous dispersion of the following materials is preparedas follows:

Material: Percent by weight EpoxyA 0.1-2.0 (active solids). Epoxy B0.1-3.0 (active solids). Epoxy C 0.1-2.0 (active solids). Glacial aceticacid 0.10.5.

Paintable silicon fluid emulsion 0.l-l.0. Gammaglycidoxypropyltrimethoxysilane 0.05-0.8. Polyvinyl acetate copolymer3.0-l0.0 (active solids). Ionic solution of AlCl 0.06-0.36 (activesolids). Deionized Water Balance.

The pH of the finished size should be from about 4.0 to about 5.0.

EXAMPLE H An aqueous dispersion is made of the following materials:

Material: Percent by weight EpoxyA 0.38 (active solids). Epoxy B 1.07(active solids). Epoxy C 0.19 (active solids). Glacial acetic acid 0.16.

Paintable silicon fluid emulsion 0.30. Gammaglycidoxypropyltrimethoxysilane 0.40. Polyvinyl acetate copolymer 6.6.Ionic solution of A101 0.18. Deionized water Balance.

The pH of the dispersion should be approximately 4.5.

The materials were mixed together by combining acetic acid with epoxiesA, B, and C. The resinous mixture was heated to 120-140" F. and thencooled, deionized water (45-65" F.) was added slowly to the heatedmixture with thorough and vigorous agitation (Lightnin mixer issuitable) until the resinous mixture inverts from a slightly viscous toa highly viscous state. Upon inversion, an additional gallon of water isadded. This mixture is agitated for about ten minutes and furtherdiluted with twenty gallons of water. Subsequently, polyvinyl acetatecopolymer, AlCl gamma glycidoxypropyltrimethoxysilane and the paintablesilicon fluid emulsion are added to the mixture. Additional water isadded in order to adjust the solids of the mixture from about 6.0 toabout 12.0 percent.

Epoxy A-This material is prepared by dissolving approximately 1,500parts by weight of the general type of epoxide shown below, having an nof 3.6 with 1,500 parts by weight of diacetone alcohol in a 4 literPyrex reactor kettle having a motor drum agitator therein and surroundedby a Glas Col heated mantle controlled by a Variac.

H: C C H-CHg- CH: OH {omwatmm} C... a @G cm I The vessel is suitablyclosed ofl, and is provided with a reflux condenser to prevent theescape of solvents and/ or reactants. Approximately 64 parts by weightof diethanolamine is added with mixing. The temperature is raised to C.with continuous mixing and held at 100 C. for one hour to provide ampletime to react all of the amine. The material produced by the abovereaction was essentially that indicated by the following formula, havinga single terminal solubilizing group at one end:

Epoxy B--This material is prepared by dissolving approximately 805 partsby weight of the general type of epoxide indicated by Structure I havingan n of about 3.6, with 345 parts by weight of xylene in a 2 liter Kimaxreactor kettle having a motor driven agitator therein and surrounded bya Glas Col heated mantle controlled by a Variac. The vessel is suitablyclosed off, and is provided with a reflux condenser to prevent theescape of solvents and/or reactants. The mixture is heated to C. withstirring to thoroughly dissolve the resin and thereafter the temperatureis raised to C. and approximately 65 parts by weight diethanolamine isadded slowly with continuous mixing. The products are held atapproximately 120 C. for about one hour to provide ample time to reactall of the amine. The material produced by the above reaction isessentially that of Structure 11 shown before, and contains apreponderance of molecules having a single terminal solubilizing groupat one end.

Thereafter a polyglycol monoester, such as a polyglycol monooleate, isadded and reacted with the remaining oxirane. Approximately 400 parts byweight of a commercially available polyethyleneglycol monooleate havinga molecular weight of about 400 is added to the reaction kettle usingabout 2.5 parts by weight of a basic catalyst (as for example potassiumcarbonate), and the mixture heated to maintain 120 C. for four hours.The resulting material has an epoxy equivalent of 3,000, indicating oneepoxy equivalent for 3,000 gms. of the material. The material producedby the above reaction is shown by the following formula showing thepreponderance of molecules that have terminal solubilizing groups atboth ends of the molecule:

HO-CHa-CH: OH

wherein x=8 to 10.

Epoxy C-This material is prepared by dissolving approximately 530 partsby weight of the general type of epoxide indicated by Structure I havingan n of about 3.6 with 390 parts of xylene in a 3 liter Pyrex reactorkettle having a motor driven agitator therein and surrounded by a GlasCol heated mantle controlled by a Variac. The vessel is suitably closedoff, and is provided with a reflux condenser to prevent the escape ofsolvents and/or reactants. The mixture is heated to 105 C. with stirringto thoroughly dissolve the resin, and thereafter the temperature israised to 120 C. and approximately 43 parts by weight of diethanolamineis added slowly with continuous mixing. The products are held atapproximately 120 C. for about one hour to provide ample time to reactall of the amine. The material P oduced by the above reaction isessentially that of Structure II shown before, and contains apreponderance of molecules having a single terminal solubilizing groupat one end.

Thereafter. a polyglycol monoester, such as a polyglycol monooleate, isadded and reacted with the remaining oxirane groups. Approximately 720parts by weight of a commercially available polyethyleneglycolmonooleate having a molecular weight of about 1,500 is added to thereaction kettle using about 2.5 parts by weight of a basic catalyst (forexample potassium carbonate) and the mixture heated to maintain 120 C.for four hours. The reaction vessel is cooled to about 200 F. and about100 parts of diacetone alcohol or other polar solvent is added and thissolution stirred while cooling to room temperature. The materialproduced by the above reaction is shown by the formula showing thepreponderance of molecules that have terminal solubilizing groups atboth ends of the molecule:

wherein x=28 to 36.

The paintable silicon fluid emulsion is commercially available under thetrade name SM-2050 from General Electric Company. Thegamma-glycidoxypropyltrimethoxysilane is commercially available underthe trade names A-187 and Z-6020 from Union Carbide Corporation andDow-Corning Corporation respectively. The polyvinyl acetatezN-methylolacrylamide copolymer emulsion is commercially available under thedesignation 25- 2828 from National Starch Company. The AlCl iscommercially available under the designation 42-2301 from NationalStarch Company.

Eight hundred sixteen continuous filament glass fibers approximately0.00050 inches in diameter were produced by attenuating molten streamsof glass at a rate of approximately 10,000 feet per minute. The glassfibers, immediately after= solidification, were pulled over a graphiteapplicator that was flooded with the aqueous dispersion given above. Thecoated fibers were brought together in a strand by the applicator, andthe strand was then wound on a rotating drum mounted on a revolvingspindle which pulled the fibers at a rate of approximately 10,000 feetper minute. A suitable traverse mechanism moved the strand back andforth across the drum to produce a coiled package approximately 12inches wide, with an inside diameter'of approximately 8 inches, anoutside diameter of approximately 12 inches, and tapered sides. Thepackage was removed from the spindle and dried in an oven at atemperature of about 265 F. for approximately 8 to hours. Thereafter thestrand was unwound from the package and chopped into one quarter inchlengths.

vent) 2011.0 Tertiary butyl perbenzoate 13.2 Benzoyl peroxide 6.0

Zinc stearate v 80.0

The resin mix was produced by charging the polyester resin to a cowlesmixer, and thereafter slowly adding the other ingredients while themixer was running to thoroughly disperse the ingredients throughout theresin.

A Molding Premix was made from the following ingredients:

Ingredients: Parts by weight Above resin mix 1763.0 Calcium carbonate-325 mesh filter 315.0 Clay filler 2832.0 fit-inch chopped strands givenabove (98% glass) 1080.0

The Molding Premix was made by adding the resin mix to a Baker-Perkinssigma blade type mixer, and adding the clay and the calcium carbonatefillers while the mixer was running. After the above ingredients weredispersed in the resin, the mixer was run for an additional 6-8 minutesto assure a uniform dispersion. Thereafter, the quarter inch choppedstrands were blended in during a 30 second period, and the mixer was runfor an additional one and onehalf minute period to assure a uniformdispersion of the strand throughout the mixture of other ingredients.The chopped strands showed a slight degree of filamentation aftermixing, which is a desirable characteristic of glass strands treatedaccording to the inventive concept.

The chemically reactive polyvinyl acetate-copolymer undergoes a highdegree of cross-linking thereby produc ing a tough, hard coating on theglass fiber strands that possesses a highly insoluble characteristicwith a resin'ous, matrix. The insolubility characteristic becomesextremely important when preparing a premix compound=andlor when aninjection molding machine is used, because it controls the degree offilamentation of glass filaments from the strand into a multiplicity ofdiscreet bundles, smaller in diameter than the original strand. Somefilamentation is desirable but too much or too little is undesirable.This desirability has been proven by conducting impact tests upon thereinforced structures. Analysis shows that impact strengths are greatestwhen there is some degree of filamentation of the glass filaments fromthe strand..

In addition to the chemically reactive polyvinyl acetate copolymer, thecombination of special epoxy resins, used in the treatment that coatsthe glass filaments, functions as a lubricant between the filaments thatmake up the glass strand. This characteristic becomes extremelyimportant when the glass strand is unwound from the dried formingpackage prior to going to the chopper. Apparently, the combination ofepoxy resins allows the polyvinyl acetate to cross-link on the strandduring drying but prevents cross-linking of the coating from strand tostrand on the forming package. Without this lubricity characteristic,there is a slight strand-to-strand bonding on the package, sufiicient instrength that upon removal of the'strand from the package, the strandseparates from itself thereby destroying its integrity, and furthermorecauses fuzzing and broken strands. When the integrity of the strand isdestroyed, the advancing strand at the chopper tends to foul the chopperthereby cutting down on the chopper efiiciency and the uniformity of thelength of chopped strands.

I claim:

1. A sizing composition for glass fibers, characterized by high abrasionresistant properties, controlled strand in.

tegrity and excellent processing and bonding properties, 10 comprisingin percent by weight:

Epoxy A, characterized by: 0.38 (active solids) HO-CHz-OH: OH I CH;

N-Gm-JQHHHOW HO-CHz-Cfia L H:

OH I CH3, 0CH-.-3H-CH20J;-0CHPC CHa wherein n= about 3.6

Epoxy B, characterized by: 1.07 (active solids). no-cm-Om on orr, on on,

N-cHPH cm oi o cm H CH2- o-i BIO-OHa-C: L H: J H;

OH O OCH=bHCHz-E0GH2--CH :+O!1(CHQ)1CH=CH(CHZ)1CH; x

wherein z==8 to 10 and wherein n==about 8.6

Epoxy 0, characterized by: 0.19 (active solids).- HO-CHr-CH: OH I" OH;OH I OH;

c1rz-i :H-cHi-o--i--o-cm-hH-cm-o-@ t HO-CHa-Cfi: L H: .L

OH 0 OCHfl-$HCHTE 0C Hz-CHz} 0-y (CH2) iii-CH;

wherein x==28 to 36 and wherein n=abont 3.6

Glacial acetic acid 0. 16 Glacial acetic acid 0. 1-0. 5 Paintablesilicon fluid emulsion 0. 30 Paintable silicon fluid emulsion 0. 1-1. 0Gamma-glycidoxypropyltrlmethoxysilane 0.40Gamma-glycidoxypropyltrimethoxysilane 0. 05-0. 8 PolyvinylacetatezN-methylol acrylamlde cepolymer--- l 6. 6 Polyvinyl acetatecopolymer 1 3. 0-10. 0 igi finiiil iitfii i B81252 isiftfnizii iiigiea-e22 1 Active solids. 1 Active solids.

2. A sizing composition for glass fibers, which when 40 3. The sizingcomposition as claimed in claim 2 wherein combined with the glass fibersyields high abrasion rethe polyvinyl acetate copolymer is a polyvinylacetatezN- sistant properties, controlled strand integrity andexcelmcthylol acrylamide copolymer.

lent processing and bonding properties, comprising in per- 4. The sizingcomposition as claimed in claim 2 wherein cent by weight: the metal acidcatalyst is a soluble metal salt of a transi- Epoxy A, characterized by:0.1-2.0 (active solids): H0-CH2-C: OH I" OH;

N-CHz-H-CHr-DW HO-CHz-C: L H: 0H CH3 0 ocni-on-czri o--b-o-cnz-ofi omEpoxy B, characterized by: 0.1-3.0 (active solids);

HO-CHa-CH: 0H CH; OH I OH;

N-cnr-cn-cmo--t-o-cnren-omO-Q-i-G HO-OHr-Ca L e in OH Oo-cm-illI-OHz-EO-CHi-OH%-0-ii-(cH2) -0H=CH(0Hz)1CH, I

wherein z=8 to 10 Epoxy 0, characterized by: 0.1-2.0 (active solids);HO--CH2-CE: OH I" CH; OH I OH;

n-om-hn-oml0t3mH-0Hw-0i.. "HO-CHz-Cfia H: in e OH 00--CH:--JJHCHgEO-CH2-CH:}O-%-(CH:)ru-CH.

wherein 2=28 to 36 1:1 12 tion metal selected from the group consistingof aluminum, 3,336,253 8/ 1967: Wong et-aalg. :26G:-:.-29-.2 'EPcalcium, titanium, vanadium, chromium, manganese, iron, 3,169,884 2/1965Mar'z'occhireral :26Qg -29'.2"EP

cobalt, nickel, copper, zinc and strontium.

References Cited UNITED STATES PATENTS 3,437,517 4/1969 Eilerman et a1.260--29.2 EP

